Process for making lubricating grease



Patented 4, 1930 UNITED STATES PATENT OFFICE EDWIN 1w; KLEMGARD, orHOLLY 04x, DELAWARE PROCESS FOR MAKING LUBRICATIN GREASE No Drawing.

This invention relates to the process of manufacturing alubricating-grease by mcorporating the aluminum salts of fatty acidswith mineral oil. The object of the inven-' 5 tion is the production ofa superior lubricating-grease which is stable to mechanical agitation asfound in gear cases, diiferentlals I and the like in use on automobiles.The

grease produced by this process isparticularly suitable for use in thelubrication of chassis-bearings, journals and a wide variety of bearingswhere the lubricant is forced to the wearing surfaces by means of highpressure, as it works thru grease guns or grease cups easily, and at thesame time its lubricating qualities are such that it stays in place andgives satisfactory lubrication-for prolonged periods of time. subject tooxidation and does not leave hard or soapy residues in small oil groovesas found in automobile, spring, shackle-bolts.

Another object of this invention is the production of alubricating-grease which is not affected by or soluble in water. In theknown 1 processes for manufacturing lubricatingreases various soaps ormetallic-salts of atty-acids, derived from vegetable or animal oils andfats, are employed for thicken i ng mineral lubricating oils. Theproportion and grade of mineral oil used-usually depends ontheconsistency required in the finished grease and the service to which thegrease is to be put. In many'cases greases are produced by boilingtogether fat or fatty oil, caustic soda solution and an appropriatequantity of mineral oil. It is of importance that these greasescontaining sodium soaps or other alkali salts of fatty acids, areaffected greatly by the presence of water, If

40 during storage or in use, sodium soap greases come in contact withmoisture, they acquire an unsatisfactory appearance, lose their originalconsistency and become thin and subject to leakage from difierentialsand gear cases. v While it has long been known that various aluminumsoaps have beenused to thicken mineral oils it should be understood thatthe methods used in the past producedliver-like jellies which whendissolved in large quan- The grease is not Applicationfiled March 17,1927. Serial No. 176,301.

tities of mineral oil were known as mineral castor oil, viscom,oil-pulp, oil thickener, gelatin, etc. These products may be recognizedin all cases by their peculiar stringy texture, forming viscous threadswhen the oily cork is removed from a bottle of the material. They arealso characterized by their non-homogeneous appearance and the propertyof rapidly losing their viscosity, particularly when heated. Theseviscous or liver-like lubricants should not be confused with the productproduced by the following process, altho in some cases the constituentsmay be almost identical.

The term aluminum soap as used in this specification and hereafter inthe following claims, refers to the, aluminum salt of such \as stearicacid, such as aluminum tri-stearate,

which may contain small quantities of aluminum tri-palmitate.- By theterm aluminum stearate ordinary commercial or technical grade whichusually'contains an appreciable quantity of aluminum palmitate'is meant.The aluminum salts of naphthenic acids are not applicable to my process,however the use '0 a small quantity of naphthenic acids derived frompetroleum and converted to aluminum naphthenate has no detrimentalvaries with the type of grease desired according to the use for which itis intended, and the grade of mineral oil employed. A' soft grease maybe made with 5% of aluminum soap,although as much as of soap may be usedfor compounding greases for special purposes. The following formula isintend- The 300 arafiine'oil preferred has the following p ysicalcharacteristics, and is obtained from Pennsylvania or-Midcontinent Icrude oil:

Gravityn' 24 B. 'Flash point 410 F. Fire point 470 F.

Saybolt viscosity at 100 F 290 seconds Cold test -l 40 F.

containers for use.

also be drawn off from the kettle thru a se- Color .No. 6 N. P A.

While this oil has been found to give very good results, parafline oilof higher viscosity or lower viscosity such as parafline oil of 100seconds Saybolt viscosity at 100 F. may be used with satisfactoryresults. Asphalt base lubricating oils and black oils do not lendthemselves to the process as well as the oils of parafline base. Theterm parafiine oil will be used hereafter to indicate a mineral oilknown to the oil trade by that name and obtained from crude oilsproduced in Pennsylvania and neighboring States and Midcontinent fields,and may have a viscosity of 80 to 3000 seconds Saybolt at 100 F.

In carrying out the process a grease kettle equipped with paddles foragitating and jacketed for high pressure steam or hot oil formaintaining the kettle contents at a tem-' perature of ap roximately 425F. is required. A kett e set in a brick furnace and heated by means ofas, oil or coke fire may also be used. J The 0 ject of heating the oiland aluminum stearate to this temperature is not only that of causingthe soap to go into solution in the oil but to dehydrate the soap tosuch an extent that the normal stringy texture of the mixture isdestroyed and a smooth product obtained.

The aluminum stearate is charged in the kettle with approximately threequarters of the mineral oil and heated to 425 F. and maintained at thistemperature for about two minutes when the balance of the oil is run in.

Heating is then discontinued and the mixture in a liquid state is runinto chilling pans or other containers to solidify without furtheragitation. Agitation is carried on while: the kettle is being heated. Ifdesired the total amount of the oil may be mixed with the aluminumstearate at thestart of the process but a darker colored product isproduced. After the grease has aquired a temperature of approximately100 F. it may be packed in The liquid grease may ries of cooling pipesto obtain a smooth prodinto iron pans about ten feet square and six"Having now described my new lubricating-'- I grease and the process formanufacturing 1t, what I claim as new and desire to protect by LettersPatent is:

1. The process of manufacturing lubricat ing-grease which comprisesmixing aluminum stearate with paratfine oil, heating the mixture to 335F. to 550F. and maintaining this temperature until the mixture ispractically dehydrated and the normal stringy texture destroyed, thencooling without appreciable agitation, substantially as described.

2. The process of manufacturing lubricating-grease which comprisesmixing 'aluminum soap'with parafiine oil, heating the mixture to 335 F.to 550 F.and maintaining this temperature until the mixture ispractically dehydrated and the normal stringy texture destroyed, thencooling without appreciable agitation, substantially as described.

3. The process of manufacturing lubricating-grease which comprisesmixing 7 .5%, by

-weight of aluminum stearate with. 92.5% of parafline oil, heatlng themixture to 425 F.

and maintaining this temperature until the mixture is practicallydehydrated and the normal stringy texture destroyed, then coolingwithout appreciable agitation, substantially as described.

4'. The process of manufacturing lubricating-grease which comprisesmixing from 5 to 25% by weight of aluminum soap with 95 to 75 ofparafline oil, heating the mixture to 335 F. to 550 F. and maintainingthis temperature until the mixture is practically dehydrated and thenormal stringy texture destroyed, then coolingwit'hout appreciableagitation.

5. The process of manufacturing lubricating-grease which comprisesmixing from 5 to 25% by weight of aluminum stearate with .95 to 75% ofparaffine oil, heating the mixture to335 F. to 550 F. and maintainingthis temperature until the mixture is practically dehydrated and thenormal stringy texture destroyed, then cooling without appreciable

